例句：
It has a clean and usable interface and has an Extensions API to extend and customize your installation.
它有一個(gè)清爽和可用的接口，并且還有一個(gè)擴(kuò)展的API可以定制你的安裝。
Someone came out with a most useful suggestion.
有人提出了一個(gè)非常有益的建議。
Please cancel the words which are useless.
請(qǐng)把無(wú)用的詞劃掉。